Color in modern man is significantly influenced by the need to absorb vitamin D when it is formed in the skin oils and absorbed into the body. This is why you should not shower for several hours after sun exposure if you want your natural D for strong bones and teeth. It is now believed that Neanderthals were blue eyed and fair skinned, enabling them to live in the North. When dark skinned Africans moved north they could not survive well until there was some mingling with the Neanderthals, conferring the light gene. This “ginger” gene is found extensively in the British Isles and Scotland. I believe my Scots ancestors husband had it in spades along with faint brow ridges, heavy bones, a very hairy body, and a warrior temperament.
It is unlikely we will ever find proof that H. Erectus had different skin colors unless they can find DNA and a relevant marker like the “ginger gene”.
Myth # 2. I get enough from the sun.
Not likely, says Dr. Ting, since sun exposure is hard to quantify and our skin doesnt absorb vitamin D as easily as we age. Healthy adults should aim to get the RDA (recommended dietary allowance) of 600-800 International Units (IU) from fortified foods like milk and cereal. Ask your doctor what dose is best for you.
Myth # 3. I sit by a window all day, so my levels are probably fine.
Actually, you wont absorb any D if youre behind glass.
http://www.healthmonitor.com/your-health/written-article/4-myths-about-vitamin-d
You are ignoring the possibility of convergent evolution. The same environmental pressures that gave the Neanderthals light skin would have been working on Africans as they moved northward. After many generations, pigmentation would have changed.
I find it hard to believe that Europeans became white solely from Neanderthals give that Neanderthal genes account for only a few percent in European genomes.